Magento XML using before/after to place blocks hardly ever works

Question

I\'m a front-end Magento dev, have built quite a few of my own themes and I want to understand Magento\'s XML block positioning better...

I normally use a loca

Answer 1

The before and after attributes only work in one of two cases:

1. When you insert into a core/text_list block
2. When your template block calls getChildHtml without any parameters

When you say

you're telling Magento

Hey Magento, put the example_block inside the root block.

When you put a number of different blocks inside a parent, those blocks have an implicit order. For template blocks, this order doesn't matter, since those blocks are being explicitly rendered.

getChildHtml('example_block') ?>

However, there's two cases where order matters. First, if you call

getChildHtml() ?>

from a template, then Magento will render all the child blocks, in order.

Secondly, there's a special type of block called a "text list" (core/text_list/Mage_Core_Block_Text_List). These blocks render all their children automatically, again in order. The content block is an example of this

That's why you can insert blocks into content and they render automatically.

So, in your example above, you're inserting blocks into the root block. The root block is a template block whose phtml template uses getChildHtml calls with explicit parameters. Therefore the before and after attributes don't do what you (and many others, including me) wish they did.